Signaling system



Jan. 6, 1931. J. R. BALSLEY 1,788,078

SIGNALING SYSTEM Filed April 12,1926

wmuzssss; INVENTOR Jc zmes R.- Ba/s/ey Rd W "13* BY- Q furtherjobject of my inventionis to Patented Jan. 6, 1931 AM S 3/ I'BALSLEY, or swIssvA E; rnNNsY'IJVA IAQ, AssIeNonrofwEs'r-IimnousE ELECTRIC & MANUFACTURING oo'MrANIg ooRPonA'rIoN- on "PENNSYLVANIL SIGNALING sYs'rEI/I Application filed April 12,

invention relates to amplifying systemsand it has particular reference to systerns of the type generally known as superregenerative, inwhich theai'nplification fob- 5 tained isenormously greater than infthe usual or simple'typeof regenerative sysis wellknown to those skilled inthe art. it isquitediflicult to tunethe system to a de-.

sired carrier frequency on account ofthe, ,5 numerous noises always present whenthe 1 ;system1s in operation.

'-.tain the greatest possible amplificatiom it is'exp'edient to keep the variationfrequency;

just'atthe edgelof audibility, which causes a whistling sound difficult to filter out even though elaborate filter networks are used. It has also been notedthat the amplification obtained by the super-regenerative system vae ries in proportion to the difference between.- erthe local variation frequency and'th'e frequency of the incoming carrier wave, and. that signals of very high .frequen cy,fcor 'ejsponding. to a wave length fofsayo lOO 1nete1is,f are amplified more than signals-on the fre quencies usually used in broadcasting if V [It isan object of myinvention to provide super-regenerative system which" will be: "simple and easy to adjust andwhic'h,-in thee;

capable of" giving extraordinarily loudfsig Anotherfobject of my invention construct a super-regenerative system that the variation frequency need .notbe audible J-Still another object of iny invention is to; provide a super-regenerative system in which; i the amplification. will be Enibstantiall-y consta nt over a wide range of frequencies.

Ithas also been foundthat in order web provide a super-regenerative. systemawhich ative system is prevented fromradiating the local variation frequency, which; radiation Lhas'proved objectionable in some cases.

. These objects as well asother s Which'will be more clearly; brought out later, I attain employ ng .a detector tube between. the

source of varying electric currentsan-dthe super-regenerative system. A tube so.located may properly be termeda blocking detectory ltuber In addition, I [make use of a local oscillation generator, the output. of which vis passed into either the grid or plate circuit Ofthis blocking tube. I

,The frequency of the. oscillation generator ,is sogchosen that the resultant frequency. obtained by nteraction with the incoming ,hlghfreq'uencyis muchhigher than suchincoming frequenGy.1v This newi irequency is then applied to-the inputcircuit of a superregenerati've system, which circuit is tuned fixed in tuning. V p

By stepping ,up incoming frequency, 1 amfenabled' to employ, a much higherfvariation frequencythan is v i lisual in the super rege ra sy tem, wh r qu cy y well above the limit. ofaudibility At the to a definitexhigh frequency and remains;

same time, ,1 am enabled to maintainfcom' stantly I a very large difference between the stepped-up frequency; and thelv-a-riation ire- 'quency of thegsuper regenerative system," which large. difference results in extremely amplification as iswell known in the art.

handsgof *evenan unskilled operator, will-bee; above, .the;superiegenerative .90 systeminput circuit is keptjtuned to'ajde'fi 7 nijte 'irequencyland it has been'foundf by,

-experiment,thatl'affrequency of three 'thoun ki oiy lesor hig r h mo ti p die'ntjto use; Leaving the input circuit'fixedos 7 h tuning controls to be majnipu jinput circ, t 'and-thatf ofthe frequency de- I termini-ngbircuit .ofthe abovem'entioned i o l ;o i -ll ien ene r 10 s r dshi hif qlle i yir 5d;a tl s acts to prevent the extremely powerful oscillations oft-he super-regenerative system from being radiated from the antenna. 1 V

V For a more complete understanding of -this 15 invention reference is made to the following 1 detailed description and claims taken in-;con-' nection with the. accompanying drawing.

I The drawingfifs' a diagram inaticlview of a I frequency changing amplifier, indicated generally at A, is interposed between a source of electric currents indicated at B,

, j and, a super- 1 -egeneratiye system indicated [at- G; An antenna 1' is connected'through' an andsuchIantenna'niayobviously be replaced ib t-l o p "(n h w'id 9 m ype of coupling to a LcOnductoi" carrying hig'h freo quen'cy currents, as my invention is not to {be limited tolasystem adapted solely: for

ground connections TQ61ip'le'd to the' inductor 2 is, shown'aninductorB'tunedfby a con-' dens -r4 I shunte'djacross the: terminalsjthere of; circuit 3, 4 isiincludedf in thefinput Tcir'cuit of, athrmionic tube 5, being: con- 7 of the tube andythrou'gh the CY batteries '8 1, n 9t; the filament' 10 gr ts sa e tube oscillationgeneratdi comprisesa ther- 1 mionic tubell haying in'its grid circuit an 12; shunted taming" "condenser V 1 3' andprovided in' 'its plate circuit, with an upledi to theindu'ctor12 in ainf oscillations therein; at a determined by the constants of a was. l agg e tireda 112,?1sr The oscillation ge to; 1; esflw u tune other {thermionic slat-011v a, swan supplied with filament p nauseous sweeten Jewels;i p in i at.a'suitablepotential. iThe potential of the It is a part of the apparatus--for-het erodyning thejncomingsignal up-lto the def "inductor 2 to This sm-trey findic- "ativ'e of a source o'f varym'g electric currents other feed back inductor 33, and the B bat V v V, y V I I V 'ftery18, A by-pass condenser 22 is connected use with the conventlonal antenna and need not be described in detail.

g Y giidgof thisoscillation generatdr'is the C battery" 9, which 1 serves tomaintain the grid 15 0f the tube ll I,

v grid Z-i$flt 11l 1 e bil e H bin fifl System 13 tuned" a e 9 tt es fi id. i he. ,c rsu t' j nst tlescribed, 1t is entirely feaslb-le to re "Coupled to this inductor l6, and electrically connected therewith, is an additional inductor 19 which is associated with-the grid 7 through a neutralizing,condenser 20, the purpo ise of which will belbr'ought outllatenin, the description. i f

The apparatus indicated to the right of the dotted line and designated by the letter C is :substantially the same as that shown in Fig.

12 of theArmstrong patent above referred to, and, asdescribed in that patent, consists of a system so arranged thata single tube performs simultaneously thefunction of amplification, generation of the variation fre- .quency, and detection. This super-regener; 'a-tive detector comprises a tube 23, *in the input circuit of which is included a circuit vcomprising an inductor 24;, shunted by a condenser 25, a C battery 26 and a-second inductor '27 1 sliunted'by 'a' condenser 28. 53 In the output circuit of this tube 23" is included serially between the plate 29 and the filament lead 30, a tickler or feed back inductor 31,,a telephone or "similar device 32, an-

from a point between the telephones 32 andthe tickler 31 to the filament of the s'uper regenerative detector tube, which shunts away from the telephones theradio frequency oscillations necessarily present in the ticker coil 7 v H a g V '31 in order to secure regeneration at'the frenectedthrough an inductor 6 to; the grid 7 quencyjto which'the circuit 24,2Qis tuned. The manner inwh ch thissuper-regenerat ve detector system functions is thoroughly explained'in the said patent to Armstrong and In operation, the "circuitcoinpesed'of the inductor 3 and tl 1e ,condenser leis tuned tothe frequency of the incoming carrier wave. The n oscillation generator his then tuned andthe coupling between inductors '6 and 12 is so adj usted that a definite and constant highfrequency potential is impressed between the grid 7. and the filament 10 of the detector tube '115 5. f'lhis frequency is, so chosen that the resultant of this interaction withjthe incoiming high frequencyis the frequency; tozwlllcl l the inputfcircuit 2 L, 25"of the superrreg'enerative 12o I For example, if the a frequency of 500 'kiloc'ycles perisecond, the

"frequency of the oscillation-generatoroll. is

made 3500 kilocycles per second 5 The differi-x 5 ence in frequency i's'theii 3000 kilocycle's per as is well known to thos'e skilled in the art,130

erative system is controlled by the constants uyvsams carries the same modulation that is carried by the original incoming signal.

Because of the rectifying action of the tube 5, the resultant frequency appears in the output inductor 16 and by reasonof the coupling existing between the inductors 16 and 24 it is impressed acrossthe grid-filament circuit of the super-regenerator detector tube 23.

The variation frequency of the super-regens 5 does not oscillate and to further prevent feedingbacktherethroughof the variation frequency, the neutralizing inductor 19 and the condenser 20 are. provided. This arrangement serves to feed back to the grid a voltage I in the proper phase to neutralize any feed back directly through the capacity existing between the plate 17 and the grid 7 and prevents local oscillations'from being set upin the circuits associated with the tube 5.

By reason of the fact that the output of the detector tube is always at a definite frequency, there is no necessity for changing the tuning of the circuits of the super-regenerative system, which may accordingly be 'adjusted to a state of maximum efliciency and left in such. adjustment. Accurate and permanent tuning fay. be secured by piezo-electric crystals'if preferred.

Although wide variation of the dimensions of the apparatus are possible, good results may be obtained over the range of frequencies now ordinarily used for broadcasting by circuits having the constants stated below. Assuming the input capacity of the tubes used as being micro-microf'arads, the inmicrofarad's.

ductor ;3 is preferably made to have an inductance of 234 microhenries while the condenser 4 should have a maximum capacity of .00035 The inductor 12 has an inductance of microhenries, while the condenser 13 should have a maximum capacity of .00012 microfarads, the inductor 14 being sufficiently large to insure steady oscillation.

The tuning range of the oscillator will accordingly be from 4500 kilocycles to 3500 kilocycles, thus permitting the efficient heterodyning of any frequency lying in "the, present broadcast range of 500 kilocycles to 1500 kilocycles. The inductors 16 and 19 are eachpreferably about one half the num,- ber of turns of the inductor '24, while the condenser 20 may have a'maximum capacity equal to grid-plate capacity oftube used.

The inductor -24 formingthe input of the super regenerative system is preferably given a value of 150 microhenries, .while'the-condenser 25 has a fixedzvalue of .00002micro The tickleri or'wfeed back inductor 31 is inadesufficiently: large to assure easy oscillation; I havefoundthat. inductor 27 may be :a 'duolat-eral coil of-.128 henries, the shunting -.-condens'er 28z havinga capacity of not less than -0015 microfarads for greatest efliciency.

-:The inductor 33 may be a s-duolateral coil of lvhenrie's; The'twoinductors'27 and33 togetherwithfconde'nser28 give a variation frequency of about 20,000 cycles per second.

' f The super-regenerati'vev system indicated at C- may obviously be-replaced byany one o'f'a-the systems: disclosed in the patent to Armstrong referred: to& previously, Fig. 12 of that patent-having beenchosen merely for -'-the* .sake'- of convenience; It isalso obvious .thata different type of oscillation generator and accompanying circuits may be used, and -it-isquite feasibleto amplify the incoming signal previous to itsbein .appliedto the grid-filament circuit of .the etector tube 5.

One of the principal advantages secured by my" invention is the ease with which the enormous amplification: of- .the' super-regenerative circuit; may beisecured, It is not nec--- essaryfor the operator to concern himself about the adjustmentslof that portion ofthe i system to .therightof thedotted line'in the draw ng; as t-his section, when once adjusted, 7 remains fixed; #In erderto pick up .anditune in on any station within range, it isionly necessaryfor thelopfator to adjust the tun-- ing of the circuit 3, 4 and the frequency of the oscillation generator.

I have found by experiment and actual demonstration that when using three tubes 7 of the type now known asR-adiotron UX199,

the amplification obtainable is equivalent to A that of the usual radio frequency amplifier employing sixor more tubes. It will thus be seen that inaddition to being simple to op.- erate, my invention proyides asystem that is extreme yeconomical.

Another feature which is advantageous is that only a small energy collector is necessary when operating a systemacc'ording to my invention. The usual antenna or loop. may be replaced by a relatively short sectionof wire, or the input circuit 3, 4 may be conductively connected to almost any extended metal surface 7 which is exposed to radiant energy. This latter feature renders my system {of great value in connection with portable sets which are to be used in places where it is impracticable to erect the usual type of re ceivin'g antenna.

Although I have illustrated and described. herein certain specific embodiments of my invention, I am fully aware that many other modifications are possible, "and my inven :tion is'lnot to :be limited exceptinsofar as -is necessitated by prior artand as indicated by the following claims. I I

Icla'mi as my'invention': -I

. 5 1. In combination, a super-regenerative detector system havingaivariationfrequency, means ion producing from an incoming sig- "nal a frequency higher thanthe carrier. wave of such signal, :and uni-directional coupling means betweenqthe. supereregenerativesystem and-the frequency raising means.

2. In combination, a super-regenerative system adapted to oscillate at a plurality of frequencies, means for raising-the frequency r of. sin-incoming signalbefore applying it to 7 V thesuper-regenerativesystem, and means for .-preyenting"theloscillations. generated by the suprI-regenerative system fromaffectingthe r irequencyiraising means. 1 a a. n 3,1111 combination, asupereregenerative. fsystem zadapt'edito .oscillate at :a plurality of frequencies'and having an input .circuit, an energy-receptor capable of radiating said'osncillations and means interposed between said 25 freceptorandzsai-dsystem for raising the frequency of mninboming-si'gnal, said last-named means comprising an: oscillation generator xa'nd airectifyingcdevice having an 'out ut 1 circuit,saidxoutputrcircuit being; so di erso entially 'coupledito the input. circuit: of'said super-regenerative system: that :oscillations vdevelop'edxin the said.- systemarezprecluded efrommeachingl said iehergfy receptor. v r In;:testimonya'whereo I'have hereunto subscribed mymamethis29thzdayoof March, I

51926.2 Y e a :JAMESaR-JBALSLEY; 

